Oxidized stannous acylates



United States Patent M 2 Claims. 01. 260-414) This invention relates toepoxide compositions and to the curing of epoxides with certain tincatalysts.

This application is a divisional application of Ser. No. 163,050,entitled, Epoxide Composition, filed Dec. 29, 1961, now Patent No.3,284,383, by W. R. Proops and assigned to the same assignee as theinstant invention.

A variety of catalysts have been suggested for use in promoting the cureor polymerization of epoxide compositions into hardened, infusible andinsoluble products of relatively high molecular weight, the cured epoxycompound being either in the form of a homopolymer or copolymer withvarious organic compounds capable of interaction with the active groupsof the epoxide. Included among the known catalysts are strongly acidicmaterials such as sulfuric acid, phosphoric acid, etc.; aromaticsulfonic acids such as toluenesulfonic acid and benzenesulfonic acid;Lewis acids, e.g., boron trifluoride, stannic chloride, etc.; and borontrifiuoride-amine complexes such as boron trifluoride-monoethylamine,boron trifiuoridepiperidine, and the like. Although these catalysts areeffective for the curing or polymerization process, their use has beenhandicapped to some extent due to a number of reasons. For example, theuse of Lewis acid catalysts such as boron trifluoride suffers thedisadvantage of effecting rapid and uncontrolled exotherms during thecure of epoxides to resins, frequently causing thermal decomposition inthe composition as evidenced by charting, or expulsion of components asindicated by bubble formation and foaming. A number of these catalystsare of a corrosive nature and cause uncontrollable gel rates in the cureof certain epoxide formulations which thus seriously limits theirindustrial application in the field of coatings, adhesives and pottingcompositions.

The present invention is based on the discovery that the productsobtained by the oxidation of stannous acylates are especially effectivecatalysts for promoting the cure of epoxide compositions. It has beenfound that the incorporation of oxidized stannous acylates in epoxidecompounds provides curable compositions which have a good working lifeand can be cured at room temperature without incurring rapid gelation oruncontrollable exotherms. The curable compositions can be spread,brushed or sprayed by techniques known in the paint, varnish and lacquerindustries, and can be advantageously used in the encapsulation ofelectrical components. In one aspect, mixtures of oxidized stannousacylates with epoxides containing the cyclohexene oxide or cyclopenteneoxide group offer a distinct advantage over epoxides of the polyglycidylether type inasmuch as they can be reacted with various hardeners andfoamed by internal development of carbon dioxide or by a blowing agentwhich vaporizes at or below the temperature of the foaming mass toprovide foamed polymers of widely varying and preselected properties.Foamed polymers of this type find wide utility in the field ofstructural reinforcement and insulation.

The catalysts which are employed in the instant invention are theproducts obtained by the oxidation of stannous acylates of the formula:

3,335,351 Patented Aug. 15, 1967 wherein R is a monovalent hydrocarbonradical, branched chain or straight chain, and containing from 1 to 54carbon atoms and more preferably from 1 to 24.

In general, the oxidation is conveniently carried out by the addition ofanhydrous oxygen to the liquid stannous acylate at a temperature of fromabout 25 C. to about C. It is necessary that dry oxygen be employed toreact with the stannous acylate, inasmuch as hydrolysis of the stannousacylate will occur in the presence of moisture. If desired, air may beused to perform the oxidation step, however, as indicated above, itshould be dried before reaction with the stannous acylate. Other organicand inorganic oxidizing agents may also be used such as, benzoylperoxide, diacetyl peroxide, potassium permanganate, and the like.

Analysis of the product obtained by the oxidation of the stannousacylates indicated that the absorption of oxygen corresponded toone-half mole of oxygen per mole of stannous acylate. The empiricalformula was confirmed by elemental analysis. However, an ebullioscopicdetermination of the molecular weight demonstrated that the oxidizedproduct had a weight twice that of the expected:

i ii SD(OCR)2 The product of oxidation was therefore either dimeric orcorresponded to the structure:

wherein R has the same value previously indicated.

The stannous acylates which are used in the preparation of the catalystsof the invention are the divalent tin salts of aliphatic monoanddicarboxylic acids which contain from 1 to 54 carbon atoms. The acidscan be saturated such as acetic acid. 2-ethylhexanoic, etc., or they maybe unsaturated acids such as oleic, linoleic, ricinoleic, and the like.

Examples of specific stannous acylates which can be oxidized to thecatalysts of this invention include: stannous acetate, stannous'propionate, stannous oxalate, stannous tartrate, stannous butyrate,stannous valerate, stannous caproate, stannous caprylate, stannousoctoate, stannous laurate, stannous palmitate, stannous stearate, andstannous oleate. Of these materials the preferred compounds are stannousacetate, stannous octoate and stannous oleate.

In carrying out the invention, the oxidized stannous acylate catalystsare mixed with epoxides to obtain a homogeneous curable composition.With epoxides that are liquid and viscous, the catalyst can be simplyadmixed with the epoxide by conventional means as, for example, bystirrers and impellers, etc. When the catalyst and epoxide areimmisicible at room temperatures; or if the epoxide is normally solid,the epoxide can be melted or mixed with a liquid organic solvent.Typical solvents include organic ethers such as diethyl ether, methylpropyl ether, etc.; organic esters such as methyl acetate, ethylpropionate, etc.; and organic ketones such as acetone and cyclohexanone,etc.

The amount of catalyst employed will vary with the cure rate desired andthe curing temperature employed. As a general guide, good results areobtained by utilizing the stannic catalyst in amounts ranging between0.001

.3 and 20 percent, preferably 0.1 to 10 percent by weight based on thetotal weight of the curable epoxide composition.

The mixture of epoxide composition and catalyst can be cured over a widetemperature range. For example, the catalyst can be added to the epoxidecomposition at room temperatures, i.e., about 15 C. to 25 C., and thecure effected, or if a rapid cure is desired the mixture can be heatedto temperatures as high as 250 C. or more. Higher temperatures above 250C. are generally undesirable due to the discoloration which may beinduced. Other single curing temperatures and combinations of curingtemperatures can be employed as desired.

The catalysts described above are used to promote the cure of a widevariety of known monoepoxide and polyepoxide compositions, the curedcomposition produced being in the form of a homopolymer, or copolymerwith an active organic hardener. The curable epoxide compositions can bemonomeric or polymeric, saturated or unsaturated, aliphatic, aromatic orheterocyclic, and can be substituted, if desired, with substituents suchas hydroxy, halide, alkyl, aryl, carboxyl, and the like. Thus, forexample, the instant invention contemplates the preparation ofhomopolymers and copolymers of monoepoxides and polyepoxides containingcyclohexene oxide,

cyclopentene oxide, bicycloheptene oxide, and cycloctene oxide groups.Also included are the epoxidized alkenes, the glycidyl ethers ofpolyhydric phenols and alcohols, epoxidized polybutadiene, epoxidizedcopolymers of butadiene, epoxidized natural oils, and the like.

In one embodiment of the instant invention the monomeric polyepoxideswhich can be cured with the catalysts contain at least two oxiraneoxygen atoms, at least one of which is bonded to two vicinalcycloaliphatic carbon atoms. The other oxygen atom is also bonded to twovicinal carbon atoms, but the carbon atoms need not necessarily formpart of a cycloaliphatic ring. Thus, the polyepoxide component containsat least two vicinal epoxy groups, i.e.,

the epoxy carbon atoms of at least one of the groups forming a portionof a cycloaliphatic hydrocarbon nucleus. The cycloaliphatic nucleuspreferably contains from 4 to 8 carbon atoms including the epoxy carbonatoms, and preferably from 5 to 7 carbon atoms.

Diepoxides which contain both oxirane oxygen atoms bonded tocycloaliphatic carbon atoms are highly preferred. Polyepoxides whichcontain solely carbon, hydrogen, and oxygen atoms are especiallypreferred. The oxygen atoms can be (in addition to oxirane oxygen)etheric oxygen, i.e., O oxygen present in an ester group, i.e.,

oxygen present in a carbonyl group, i.e.,

and the like. A single polyepoxide or a mixture of at least twopolyepoxides can be employed in the novel curable compositions.

Illustrative polyepoxides include, for example, the alkanediol bis3,4-epoxycyclohexanecarboxylates the alkenediolbis(3,4-epoxycyclohexanecarboxylates), the alkanediol bis(lower alkylsubstituted-3,4-epoxyclohexanecarboxylates), the oxaalkanediol bis(loweralkyl substituted-3,4-epoxycyclohexanecarboxylates),

the alkanetriol tris 3,4-epoxycyclohexanecarboxylates the alkenetrioltris(3,4-epoxycyclohexanecarboxylates), the alkanetriol tris (loweralkyl substituted-3,4-epoxyclohexanecarboxylates), the oxaalkanetrioltris(3,4-epoxycyclohexanecarboxylates), the oxaalkanetriol tris (loweralkyl substituted-3,4-epoxycylohexanecarboxylates), and the like. Theabove-illustrated polyol poly(3,4-epoxycyclohexanecarboxylates) can beprepared by epoxidizing the corresponding polyolpoly(cyclohexenecarboxylate) with at least a stoichiometric quantity ofperacetic acid (preferably contained as solution in ethyl acetate) percarbon to carbon double bond of said polyolpoly(cyclohexenecarboxylate), at a temperature in the range of fromabout 25 to C., for a period of time sufiicient to introduce oxiraneoxygen at the sites of all the carbon to carbon double bonds containedin the polyol poly(cyclohexenecarboxylate) reagent. The polyolpoly(cyclohexenecarboxylates), in turn, can be prepared in accordancewith well known condensation techniques, e.g., the esterification of apolyol, e.g., ethylene glycol, diethylene glycol, triethylene glycol,tetraethylene glycol, 1,2- propylene glycol, 1,3-propylene glycol, thepolyoxyethylene glycols, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, the octanediols, the octadecanediols, the butenediols, thepentendiols, the hexenediols, the octenediols, 1,2,3-propanetriol,trimethylolmethane, 1,1,l-trimethylolethane, l,1,1-trimethylolpropane,1,26-hexanetriol cycloaliphatic triols aromatic triols, and the like;with a 3-cyclohexenecarboxylic acid, e.g., 3-cyclohexenecar boxylicacid, lower alkyl substituted-3-cyclohexenecarboxylic acid, and thelike. The expression lower alkyl, as used in the disclosure, means analkyl radical which contains from 1 to 4 carbon atoms.

Other polyepoxides contemplates include, for instance, thebis(3,4-epoxycyclohexylmethyl) hydrocarbon dicarboxylates and thebis(lower alkyl substituted-3,4-epoxycyclohexylmethyl) hydrocarbondicarboxylates, e.g., bis (3,4-epoxycyclohexylmethyl) oxalate,bis(3,4-epoxycyclohexylmethyl) malonate, bis(3,4- epoxycyclohexylmethyl)succinate, bis(3,4-epoxycyclohexylmethyl) glutarate,bis(3,4-epoxycyclohexylmethyl) adipate, bis(3,4- epoxycyclohexylmethyl)maleate, bis(3,4-epoxycyclohexymethyl) tetrahydrophthalate,bis(3,4-epoxycyclohexylmethyl) citraconate, bis(3,4epoxycyclohexylmethyl) isocitraconate, bis(3,4 epoxy 6methylcyclohexylmethyl) furnarate, bis(3,4-epoxycyclohexylmethyl)pirnelate, bis(3,4-epoxycyclohexylmethyl) terephthalate,bis(3,4-epoxycyclohexylmethyl) azelate, bis(3,4epoxycyclohexylmethyl)sebacate, bis(3,4-epoxycyclohexylmethyl) itaconate,bis(3,4-epoxycyclohexylmethyl) hexahydrophthalate,bis(3,4-epoxycyclohexylmethyl) pathalate, bis(3,4-epoxycyclohexylmethyl)glutaconate, bis(3,4- epoxycyclohexylmethyl) hydromuconate, and thelike.

Other desirable polyepoxides include the monoesters of 3,4epoxycyclohexylmethanols and 3,4 epoxycyclohexane carboxylic acids suchas, for example, 3,4-epoxycyclohexylmethyl3,4-epoxycyclohexanecarboxylate, l-methyl- 3,4 epoxycyclohexylmethyl1-methyl-3,4-epoxycyclohexanecarboxylate, 6-methyl 3,4epoxycyclohexylmethyl 6- methyl 3,4 epoxycyclohexanecarboxylate, 2ethyl-3,4- epoxycyclohexylmethyl2-ethyl-3,4-epoxycyclohexanecarboxylate,4-n-propyl-3,4-epoxycyclohexylmethyl 4-n-propyl 3,4epoxycyclohexanecarboxylate, 5 isobutyl- 3,4 epoxycyclohexylmethyl 5isobutyl 3,4 epoxycyclohexanecarboxylate, lower alkyl substituted3,4-epoxycyclohexylmethyl lower alkylsubstituted-3,4-epoxycyclohexanecarboxylate, halosubstituted-3,4-epoxycyclohexylmethyl halo substituted-3,4-epoxycyclohexanecarboxylate, 1-chloro-3,4-epoxycyc1ohexylmethyl1-chloro-3,4-epoxycyclohexanecarboxylate,2-bromo-3,4-epoxycyclohexylmethyl2-bromo-3,4-epoxycyclohexanecarboxylate, and the like.

Still other desirable polyepoxides include, by way of illustration,

the 3-oxatetracyclo [4.4.0.l' l lundec-8-yl vicinal epoxyalkyl ethers,

the 3-oxatetracyclo [4.4.0.1 .0 ]undec-8-yl vicinalepoxycycloalkylethers,

the 3-oxatetracyclo [4.4.0.1' .0 undec-8-yl vicinal--epoxycycloalkylalkyl ethers,

the 3-oxatetracyclo[4.4.0.1 .0 ]undec-8-yl 3- oxatricyclo [3.2. l .0oct-6-yl ethers,

the 3-oxatetracyclo[4.4.0.1 .0 ]undec-8-yl 3-oxatricyclo[3.2.10oct-6-ylalkyl ethers,

and the like.

Specific examples include 3-oxatetracyclo[4.4.0.l' .0 ]'undec-8-yl2,3-epoxypropyl ether,

3-oxatetracyclo [4.4.0. 1 .0 undec-8-yl 3,4-epoxybutyl ether,

3-oxatetracyclo[4.4.0.l .0 ]undec-8-yl 2,3-epoxybutyl ether,

3-oxatetracyclo[4.4.0.l .0 ]undec-8-yl 3,4-epoxyhexyl ether,

3-oxatetracyclo [4.4.0. 1' .0 undec-8 -yl 5,6-epoxyhexyl ether,

3-oxatetracyclo[4.4.0.1' .0 ]undec-8-yl 7,8-epoxyoctyl ether,

3-oxatetracyclo [4.4.0. 1 .0 undec-8-yl Z-methyl- 2,3-epoxypropyl ether,

3-oxatetracyclo [4.4.0. l' .0 ]undec-8-yl Z-ethyl- 2,3-epoxyhexy1 ether,

3-oxatetracyclo[4.4.0.1 ".O ]undec-8-yl 9, 1 0epoxystearyl ether,

3-oxatetracyclo[4.4.0.1 .0 ]undec-8-y1 9,10, 12,13 -diepoxysteryl ether,

3-oxatetracyclo [4.4.0. 1 .0 undec-8 -yl 2,3-epoxycyclopentyl ether,

3 -oxatetracyclo [4.4.0. 1 .0 undec-S-yl 2,3-epoxycyclopentylmethyether,

3 -oxatetracyclo [4.4.0. 1 .0 undec-8-yl alkyl substituted3,4-epoxycyclohexyl ether,

3-oxatetracyclo [4.4.0.1' .0 ]undec-8-yl 3,4-epoxycyclohexyl ether,

3-oxatetracyclo [4.4.0.l' .0 ]undec-8-yl 2,3-epoxycyclohexyl ether,

3-oxatetracyclo[4.4.0.1 .0 ]undec-8-yl 3,4-epoxycyclohexylmethyl ether,

3-oxatetracyclo [4.4.0. 1 .0 undec-8-yl 6-methyl-3,4-epoxyclohexylmethyl ether 3-oxatetracyclo [4.4.0. 1 0 1 undec-8-ylS-methyl- 3,4-epoxycyclohexylmethyl ether,

3 -oxatetracyclo [4.4.0. l .0 ]undec-8-y1 alkyl substituted3-oxatracyclo [3.2.1.0 ]oct-6-yl ether,

3-oxatetracyclo[4.4.0.1 .0 ]undec-8-yl 3-oxatricyclo[3.2.1.0 ]oct-6-ylether,

and the like.

Examples of other monomericpolyepoxides, include 1,4-bis(2,3-epoxypropoxy benzene, 1,3-bis(2,3-epoxypropoxy)benzene,4,4-bis(2,3-epoxypropoxy) diphenyl ether, l,8-bis(2,3-epoxypropoxy)octane, 1,4-bis(2,3-epoxypropoxy) cyclohexane, 4,4-bis(2-hydroxy-3,4-epoxybutoxy) diphenyl dimethylmethane,1,3-bis(4,5-epoxypentoxy)-- chlorobenzene,1,4-bis(3,4-epoxybutoxy)-2-chlorocyclohexane,1,3-bis(2-hydroxy-3,4-epoxybutoxy)benzene, 1,4- bis 2-hydroxy-4,5-epoxypentoxy) benzene.

Examples of vic-epoxyhydrocarbyl substituted aromatic hydrocarbons andhalo-substituted aromatic hydrocarbons include, among others,1,4-bis(2,3-epoxypropyl)benzene, 1,4-bis(2,3-epoxycyclohexyl)benzene,1,4-bis(2,3-epoxybutyl)benzene, 1,3-bis(2,3-epoxypropyl)benzene,1,4-bis- (2,3 -epoxyhexyl)benzene, 1 (3,4 epoxypentyl) 4-(2,3-epoxypropyl)benzene, 1,2-di(2,3-epoxypropyl)benzene, 4,4 bis(2,3epoxypropyl) diphenyl, 1,5 bis(2,3- epoxypropyl)naphthalene,2,6-bis(2,3-epoxypropyl)naphthalene,1,4-bis(2,3-epoxypropyl-2,3,5,6-tetramethyl benzene, and the like.

6 i The epoxidized polymers which can be cured with the oxidizedstannous acylate catalysts of this invention are polymeric moleculeswhich contain, on the average, at least one vicinal epoxy group, i.e.,

and preferably, a plurality of vicinal epoxy groups. These epoxidizedpolymers can be prepared by the epoxidation of the correspondingolefinically unsaturated polymer precursor which has an averagemolecular weight in the range of from about 250 to about 250,000, andhigher, preferably from about 250 to about 25,000, and preferably still,from about 500 to about 10,000. The term average is to be noted sincethe individual molecules of a given sample of olefinically unsaturatedpolymeric product which result from the polymerization reaction of theappropriate monomeric reagent(s), in general, vary in molecular weight(or degree of polymerization). Consequently, the overall molecularweight of the sample is the average of the molecular weight of theindividual polymeric molecules which comprise said sample.

In a broad aspect, the epoxidized polymers which are contemplatedinclude, among others, the partially'to cs sentially completelyepoxidized polymers of conjugated dienes; the partially to essentiallycompletely epoxidized copolymers of conjugated dienes with olefinicmonomers; and the like. The term polymer, as employed herein includingthe appended claims, is used in its generic sense to encompasshomopolymers and copolymers. It is pointed out, also, that the termpartially to essentially completely epoxidized (polymers or copolymers)means that the epoxidized polymers which are useful in the invention canrange from those which contain, on the average, at least one singlevicinal epoxy group and, on the average, a plurality of ethylenic groupsto those which contain, on

the average, a plurality of vicinal epoxy groups and rela tively few, ornone, ethylenic groups. As a practical matter, especially from acommercial standpoint, it is somewhat difiicult and expensive to fullyand completely epoxidize the olefinically unsaturated polymer precursor.

In one aspect, the epoxidized polymers which are contemplated as acomponent(s) in the novel curable compositions contain at least onepercent oxirane oxygen to below about 23 percent oxirane oxygen, andpreferably, from about 3 to about 12 percent oxirane oxygen. The termpercent oxirane oxygen designates the number of grams of oxirane oxygenper grams of a sample of epoxidized polymer. The upper limit regardingthe percent oxirane oxygen is a variable which will depend upon theaverage molecular weight of the olefinically unsaturated polymerprecursor, the degree of epoxidation of the olefinically unsaturatedpolymer precursor, the monomers employed to prepare said precursor, thedegree and number of side reactions which can occur during theepoxidation reaction other than that of introducing oxirane oxygen atthe site of the ethylenic carbon to carbon double bond of saidprecursor, and the like. Nevertheless, the inyention contemplates theuse of essentially completely epoxidized polymers, and consequently, thedetermination of the upper limit of percent oxirane oxygen is readilydetermined via ordinary experimentation by a chemist. However, it mustbe borne in mind that with regard to the upper limit of percent oxiraneoxygen, this limit is a variable governed by practical and readilydetermined factors such as those illustrated above.

The conjugated dienic monomers which are useful in preparing thenon-epoxidized polymers, i.e., the olefinically unsaturated polymerprecursors, are characterized by the unit,

whereas the olefinic monomers are characterized by at least one unit. Itis apparent, therefore, that the olefinic monomer can contain more thanone unit; however, said olefinic monomer is non-conjugated. It isdesirable to exclude conjugated dienic monomers which contain so-callednegative substituents, e.g., chloro, bromo, and cyano, monovalentlybonded to the carbon atoms designated by the numerals 2 and 3 of theunit Such conjugated dienic monomers can undergo what is known as1,4-addition polymerization, e.g., in the homopolymerization of1,3-butadiene, to yield a polymer containing the unit 1 I I co=o-o l l lI 1 2 3 4 However, the presence of negative groups on the ethyleniccarbon atoms of polymers which result from the 1,4-addition route tendsto inactivate the ethylenic group toward epoxidation, i.e., theintroduction of oxirane oxygen at the site of the resulting carbon tocarbon double bond is dilficult when negative groups are attached to theethylenic carbon atoms of the polymer.

Specific illustrative conjugated dienic monomers which are useful in thepreparation of the non-epoxidized polymers include, for example,1,3-butadiene, 1-methyl-1,3- butadiene, 2-methyl-1,3-butadiene,2-ethyl-l,3-butadiene, 1,1 dimethyl-l,3-butadiene,1,4-dimethyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene,2-isopropyl-1,3-butadiene, ln-propyl-1,3-butadiene,1-phenyl-1,3-butadiene, 1-ethoxy- 1,3-butadiene,l-acetoxy-l,3-butadiene, 1-allyl-1,3-butadiene,Z-methyl-6-methylene-2,7-octadiene, and the like. Conjugated dienichydrocarbon monomers which contain from 4 to 8 carbon atoms arepreferred in the preparation of the non-epoxidized homopolymers andcopolymers. Conjugated butadiene is most preferred.

Exemplary olefinic monomers which are useful in the preparation of thenon-epoxidized copolymers include, for instance, ethylene, propylene,isobutylene, butene-l, styrene, vinyltoluene, isopropenylbenzene,4-vinylcyclohexene, divinylbenzene, vinyl chloride, allyl chloride,alphamethylstyrene, alpha-chlorostyrene, 2,5-dichlorostyrene, 4-cyanostyrene, Z-hydroxystyrene, 2-acetoxysty1'ene,chlorotrifluorethylene, vinylidene chloride, vinyl fluoride, vinylidenefluoride, vinyl bormide, methyl acrylate, methyl methacrylate, ethylmethacrylate, octyl methacrylate, methyl crotonate, butyl crotonate,ethyl crotonate, dimethyl maleate, dibutyl maleate, dioctyl maleate,diethyl chloromaleate, diethyl fumarate, vinyl acetate, vinyl butyrate,vinyl 2-ethylhexanoate, vinyl stearate, vinyl oleate, vinyl linoleate,vinyl benzoate, vinyl crotonate, allyl acetate, acrylonitrile,methylacrylonitrile, acrylamide, methacrylamide, crotonamide,N-vinylbenzamide, N-vinylbutyramide, methyl vinyl ketone, methylisopropenyl ketone, acrolein, vinyl ethyl ether, vinyl butyl ether,2-vinylpyridine, N-vinylcarbazole, and the like. Preferred olefinicmonomers include the alkenes, the phenyl substituted-alkenes, theolefinically unsaturated organic esters, the olefinically unsaturatedamides, the olefinically unsaturated nitriles, and the like. Styrene,the lower alkyl acrylates, and the alkenes which contain up to carbonatoms are most preferred.

The preparation of the non-epoxidized homopolymers and copolymers iswell documented in the literature. For examples U.S. Patents 2,500,933,2,586,594, and 2,631,175 are illustrative of the reagents and modes forpreparing various non-epoxidized polymers. Liquid polybutadiene whichhas an average molecular weight of at least 250 is highly preferred.

The preparation of the epoxidized polymers which are employed as acomponent(s) in the novel curable, polymerizable compositions can beaccomplished by epoxidizing the corresponding olefinically unsaturatedhomopolymer or copolymer precursors such as those exemplified previouslywith well known epoxidizing agents, and preferably with organicperacids. Since the epoxidation reaction is carried out in a liquidphase, practical considerations are readily suggested to the chemistskilled in the epoxy art. Thus, if the olefinically unsaturatedhomopolymer or copolymer precursor is a liquid, then an inert normallyliquid organic solvent is not essential, though one can be employed ifdesired. However, if the unsaturated homopolymer or copolymer precursoris a solid, then said solid precursor should be soluble in an inertnormally liquid organic vehicle in order for it to undergo effectiveepoxidation. Inert organic vehicles such as chloroform, toluene,benzene, ethylbenzene, xylene, acetone, methyl ethyl ketone, butylacetone, ethyl acetate, and the like, are illusstrative of the commonsolvents which may be employed. The particular homopolymer or copolymerprecursor, its degree of polymerization, i.e., its average molecularweight, its preparation, and other factor, will influence, to a largeextent, the solubility of said precursor in any given inert normallyliquid organic vehicle. It is readily recognized by polymer chemiststhat many highly polymerized compounds are solids of extremely limitedsolubility in otherwise useful inert organic media, and in this respect,a practical upper limit is imposed on the degree of polymerization ofthe olefinically unsaturated homopolymer or copolymer precursor. Thus,the solid nonepoxidized olefinically unsaturated polymers which arecontemplated are soluble in an inert normally liquid vehicle, the choiceof said inert normally liquid vehicle being readily determined by themerest of routine experimentation by the artisan in the epoxy art.

Other useful polyepoxides include epoxides derived from natural oils,such as linseed oil epoxide, soybean oil epoxide, safflower oil epoxide,tung oil epoxide, castor oil epoxide, lard oil epoxide, and the like,which are glycerides containing 45 to carbon atoms.

The catalysts of the instant invention can also be employed to curemonepoxides, i.e., compounds containing only one vicinal epOXy group,which may be present as part of a cycloaliph-atic nucleus or part of analiphatic chain. Typical monoepoxide compounds include ethylene oxide,propylene oxide, 1,2-epoxyoctane, cyclohexene oxide, 1,2-epoxypropylbenzene, and the like.

It should be noted that the aforementioned epoxides are given only forpurposes of illustrating the wide variety of monoepoxides andpolyepoxides which can be cured by the catalysts of the instantinvention and no unnecessary limitations are to be inferred therefrom.

The epoxides with the oxidized stannous acylate catalyst of the typeillustrated above can be homopolymeriz/ecl or copolymerized with anactive organic hardener or combination of active organic hardeners, Bythe term active organic hardener, as used herein, is meant an organiccompound which contains two or more groups which are reactive with epoxygroups. The active organic hardeners illustrated hereinafter areemployed in a curing amount, that is, an amount which is sufficient tocause the epoxide system containing the active organic hardener(s) tobecome polymerized. The active organic hardeners can also be employed invarying amounts so as to give a wide variety of properties to the curedepoxide system. Typical groups which are reactive with epoxygroupsareactive hydrogen groups such as hydroxyl groups, carboxyl groups,amino groups, thiol groups, and the like; and isocyanate groups,isothiocyanate groups, halide atoms of acyl halides, and the like,Oxydicarbonyl groups such as those contained by polycarboxylic acidanhydrides are also active with epoxy groups. One oxydicarbonyl groupwill react with two epoxy groups and, in this connection, polycarboxylicacid anhydrides need only contain one oxydicarbonyl group in order tofunction as an active organic hardener with the epoxide compositions ofthis invention. Stated differently, one oxydicarbonyl group of ananhydride is equivalent to two epoxy-reactive groups.

Representative active organic hardeners include polyfunctional amines,polycarboxylic acid, polycarboxylic acid anhydrides, polyols, i.e.,polyhydric phenols and polyhydric alcohols, polythiols, polyisocyanates,polythioisocyanates, polyacyl halides and others. By the termpolyfunctional amine, as used herein, is meant an amine having at leasttwo active amino hydrogen atoms which can be on the same nitrogen atomor different nitrogen atoms.

Resins having particularly valuable properties can be formed frommixtures containing the epoxide compositions and polyfunctional aminesin such relative proportions as provide from 0.2 to 5.0 amino hydrogensof the amine for each epoxy group contained by said epoxide composition.It is preferred to form resins from curable mixtures containing theepoxide compositions and polyfunctional amines which provide from 0.3 to3.0 amino hydrogens for each epoxy group.

Among the polyfunctional amines contemplated as active organic hardenersinclude the aliphatic amines, aromatic amines, ara-lkyl amines,cycloaliphatic amines, alkaryl amines, aliphatic polyamines includingpolyalkylene polyamines, amino-substituted aliphatic alcohols andphenols, polyamides, addition products of polyamines and low molecularweight epoxides containing oxirane oxygen linked to vicinal carbonatoms, and others.

Typical aliphatic amines include methylamine, ethylamine, propylamine,isopropylamine, butylamine, isobutyla-mine, 2-ethy1hexylamine,3-propylheptylamine, and the like.

Examples of aromatic amines, aralkyl amines and alkaryl amines include,among others, aniline, o-hydroxyaniline, m-toluidine, 2,3-xylidine,benzylamine, phenethylamine, l-naphthylamine, meta-,orthoandparaphenylenediamines, 1,4 naphthalenediamine, 3,4 toluenediamine andthe like.

Illustrative cycloaliphatic amines include cyclopentylamine,cyclohexylamine, p-menthane-l,8 diamine and others.

Among the polyamides, i.e., those having an average molecular weightrange from about 300 to about 10,000, include condensation products ofpolycarboxylic acids, in particular, hydrocarbon dicarboxylic acids suchas malonic acid, succinic acid, glutaric acid, adipic acid, dilinolenicacid, and the like, with polyamines, particularly diamines such asethylenediamine, propylenediamine, and the like.

Aliphatic polyamines include ethylenediamine, propylenediamine,butylenediamine, pentylenediamine, hexylenediamine, octylenediamine,nonylenediamine, decylenediamine, and the like. Polyalkylene polyamines.such as diethylenetriamine, triethylenetetramine, tetraethylpentamine,dipropylenetriamiue, and the like, are particularly suitable.

The amino-substituted aliphatic alcohols and phenols suitable for use inthe present invention are illustrated by Z-aminoethanol,Z-aminopropanol, 3-aminobutanol, 1,3- diamino-Z-propanol, 2-aminophenyl,4-aminophenyl, 2,3- diaminoxylenol, and the like.

Other illustrations of polyfunctional amines are the addition productsof polyamines, in particular, diamines and triamines and epoxidescontaining oxirane oxygen linked to vicinal carbon atoms such asethylene oxide, propylene oxide, butadiene dioxide, diglycidyl ether,epoxidized soybean oil, epoxidized safflower oil, and polyglycidylpolyethers such as those prepared from polyhydric phenols andepichlorohydrin. Particularly useful polyfunctional amines are themonoand polyhydroxyalkyl polyalkylene and arylene polyamines which canbe prepared by the addition reaction of polyalkylene polyamines, arylenepolyamines, and the like, e.g., ethylenediamine, propylenediamine,diethylenetriamine, hexamethylenediamine, triethylenetetramine,tetraethylenepentamine, phenylenediamine, methylenedianiline,xylenediamine, and the like, with ethylene oxide or propylene oxide suchthat the resulting amine adduct contains two or more active hydrogenatoms attached to either one or more amino nitrogen atoms.

Examples of stillother polyfunctional amines suitably adaptable include,among others, heterocyclic nitrogen compounds such as piperazine,2,5-dimethylpiperazine, and the like; aminoalkyl-substitutedheterocyclic compounds such as N-(aminopropyl)morpholine,N-(aminoethyl)morpholine, and the like; amino-substituted heterocyclicnitrogen compounds such as melamine,2,4-diamino-6-(aminoethyl)pyrimidine, and the like; dimethylurea,guanidine, p,p sulfonyldianiline, 3,9-bis-(aminoethyl)spirobimetadioxane, hexahydrobenzamide, and others.

Other polyfunctional amines having a total of at least two active aminohydrogen atoms to the molecule can be employed in the epoxidecompositions of this invention. For example, such polyfunctional aminesas mixtures of p,p -methylenedianiline and m-phenylenediamine, or othermixtures of two or more polyfunctional amines can be used.

Another class of active organic hardeners which can be reacted with theepoxide compositions above, are the polycarboxylic acids. By the termpolycarboxylic acid, as used herein, is meant a compound or polymerhaving two or more carboxyl groups to the molecule. Curable mixtures canbe formed from the epoxide compositions and polycarboxylic acids, whichmixtures can be cured to produce a wide variety of useful products.Valuable resins can be made from mixtures containing such amounts of anepoxide composition and polycarboxylic acid as to provide 0.3 to 1.25carboxyl groups of the acid for each epoxy group contained by the amountof the epoxide composition. It is preferred, however, to make resinsfrom curable mixtures which contain such amounts of polycarboxylic acidsand epoxide compositions as to provide 0.3 to 1.0 carboxyl groups of theacid for each epoxy groups from the epoxide composition.

Representative polycarboxylic acids include oxalic acid, malonic acid,succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid,azelaic acid sebacic acid, alkylsuccinic acids, alkenylsuccinic acids,ethylbutenylsuccinic acid, maleic acid, fumaric acid, itaconic acid,citraconic acid, mesaconic acid, glutaconic acid, ethylidenemalonicacid, isopropylidenemalonic acid, allylmalonic acid, muconic acid,alphahydromuconic acid, betahydromuconic acid, diglycollic acid,dilactic acid, thiodiglycollic acid, 4-amyl-2,5-heptadienedioic acid,3-hexynedioic acid, 1,2-cyclohexanedicarboxylic acid,l,4-cyclohexanedicarboxylic acid, 2-carboxy 2 methyl-cyclohexaneaceticacid, phthalic acid, isophthalic acid, terephthalic acid,tetrahydrophthalic acid, tetrachlorophthalic acid, 1,8naphthalenedicarboxylic acid, 3-carboxycinnamic acid,1,2-naphthalenedicarboxylic acid, 1,1,5-pentanetricarboxylic acid,l,2,4-hexanetricarboxylic acid, 2-propyl-l,2,4-pentanetricarboxylicacid, 5-octene- 3,3,6-tricarboxylic acid, l,2,3-propanetricarboxylicacid, 1,2,4--benzenetricarboxylic acid, 1,3,5-benzenetricarboxylic acid,3-hexene-2,2,3,4-tetracarboxylic acid, 1,2,3,4-

benzenetetracarboxylic acid, 1,2,3,S-benzenetetracarboxylic acid,benzenepentacarboxylic acid, benzenehexacarboxylic acid, polymerizedfatty acids derived from natural oils, e.g., linseed oil, tung oil,soybean oil, dehydrated castor oil, etc., including mixtures thereof,which have a molecular weight within the range of 500 to 5000, and thelike, such as the dimer and trimer acids of commerce.

Also, as polycarboxylic acids useful in the polymerizable compositionsthere are included compounds containing ester groups in addition to twoor more carboxy groups which can be termed polycarboxy polyesters ofpolycarboxylic acids, such as those listed above, or the correspondinganhydrides of said acids, esterified with polyhydric alcohols. Stated inother words, by the term polycarboxy polyesters, as used herein is meantpolyesters containing two or more carboxy groups per molecule. Thesepolycarboxy polyesters can be prepared by known condensation procedures,employing mol ratios favoring greater than equivalent amounts ofpolycarboxylic acid, or anhydride. More specifically, the amount ofpolycarboxylic acid, or anhydride, employed in the esterificationreaction should contain more carboxy groups than are required to reactwith the hydroxyl groups of the amount of polyhydric reactant.

Polyhydric alcohols which can be employed in preparing these polycarboxypolyesters include dihydric alcohols such as ethylene glycol, diethyleneglycol, triethylene glycol, tetraethylene glycol, 1,2-propylene glycol,1,3-propylene glycol, dipropylene glycols, tripropylene glycols,polyoxyethylene glycols, polyoxypropylene glycols, 1,2- butylene glycol,1,4-butylene glycol, pentane-1,5-diol, pentane-2,4-diol,2,Z-dimethyltrimethylene glycol, hexane-1,4- diol, hexane-1,5-diol,hexane-1,6-diol, hexane-2.5-diol, 3- methylpentane-l,5-diol,2-methylpentane-2,5-diol, 3-methylpentane-2,5-diol,2,2-diethylpropane-1,3-diol, 2,2-diethylhexane-1,3-diol,2,5-dimethylhexane-2,5-diol, octadecane- 1,12-diol, 1-butene-3,4-diol,2-butene-1,4-diol, Z-butyne- 1,4-diol, 2,5-dimethyl-3-hexyne-2,5-dioland the like; trihydric alcohols such as glycerol, trimethylolethane,hexane-1,2,6-triol, 1,1,1-trimethylolpropane, and the ethylene oxide andpropylene oxide adducts thereof; tetrahydric compounds such aspentaerythritol, diglycerol and the like; and high polyhydric compoundssuch as pentaglycerol, dipentaerythritol, polyvinyl alcohols and thelike. Additional polyhydric alcohols useful in making polycarboxypolyesters can be prepared by the reaction of epoxides, e. g.,diglycidyl diethers of 2,2-propane bisphenol, and reactivehydrogen-containing organic compounds, e.g., amines, polycarboxylicacids, polyhydric compounds and the like. In forming the polycarboxypolyesters, it is preferable to use a dihydric, trihydric or tetrahydricaliphatic or oxaaliphatic alcohol. The mol ratios in which thepolycarboxylic acid or anhydride can be reacted with polyhydric alcoholsin preparing polycarboxylic polyesters useful in the compositions arethose which provide polyesters having more than one carboxy group permolecule.

Curable mixtures containing the epoxide compositions and polycarboxylicacid anhydrides can also be employed to produce resins havingdiversified and valuable properties. Particularly valuable resins can bemade from mixture containing such amounts of polycarboxylic acidanhydride and epoxide compositions as to provide 0.2 to 3.0 carboxyequivalent of the anhydride for each epoxy group of the epoxidecomposition. It is preferred, however, to make resins from curablemixtures which contain such amounts of polycarboxylic acid anhydride andepoxide composition as to provide 0.4 to 2.0 carboxy equivalent ofanhydride for each epoxy group contained by the amount of epoxideconcentration.

Typical polycarboxylic acid anhydrides include succinic anhydride,glutaric anhydride, propylsuccinic anhydride,

12 methylbutylsuccinic anhydride, hexylsuccinic heptylsuccinicanhydride, pentenylsuccinic octenylsuccinic anhydride, nonenylsuccinicanhydride, alpha, beta-diethylsuccinic anhydride, maleic anhydride,chloromaleic anhydride, dichloromaleic anhydride, itaconic anhydride,citraconic anhydride, hexahydrophthalic anhydride, hexachlorophthalicanhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalicanhydride, tetrachlorophthalic anhydride;hexachloroendomethylenetetrahydrophthalic anhydride, otherwise known aschlorendic anhydride, tetrabromophthalic anhydride, tetraiodophthalicanhydride; phthalic anhydride, 4-nitrophthalic anhydride, 1,2-naphthalicanhydride; polymeric dicarboxylic acid anhydrides, or mixed polymericdicarboxylic acid anhydrides such as those prepared by theautocondensation of dicarboxylic acids, for example, adipic acid,pimelic acid, sebacic acid, hexahydroisophthalic acid, terephthalicacid, isophthalic acid and the like. Also, other dicarboxylic acidanhydrides, useful in our polymerizable compositions include theDiels-Alder adducts of maleic acid and alicyclic compounds havingconjugated double bonds, e.g.methy1bicyclo-[2.2.1]heptene-2,3-dicarboxylic anhydride.

Thermoset resins can be prepared from mixtures containing the epoxidecompositions and polyols by providing 0.1 to 2.0, preferably from 0.2 to1.5, hydroxyl groups of the polyol for each epoxy group contained by theamount of the epoxide composition. By the term polyol, as used herein,is meant an organic compound having at least two hydroxyl groups whichare alcoholic hydroxyl groups, penolic hydroxyl groups, or bothalcoholic and phenolic hydroxyl groups. The epoxide composition andpolyol can be mixed in any convenient manner. A preferred method,however, is to mix the polyol and epoxide composition in the liquidstate so as to obtain a uniform mixture. In forming this mixture, it maybe necessary to raise the temperature of the polyol and epoxidecomposition to at least the melting point or melting point range of thehighest melting component. Temperatures below about C. are preferred soas to avoid possible premature curing of these curable mixtures.Stirring also aids the formation of a homogeneous mixture.

Representative polyols include ethylene glycol, diethylene glycol,polyethylene glycols, propylene glycol, dipropylene glycol,polypropylene glycols, trimethylene glycols, butanediols, pentanediols,12,13-tetracosanediol, glycerol, polyglycerols, pentaerythritol,sorbitol, polyvinyl alcohols, cyclohexanediols, inositol,dihydroxytoluenes, resorcinol, catechol,bis(4-hydroxyphenyl)-2,2-propane, bis(4-hydroxyphenyl)methane, and theethylene and propylene oxide adducts thereof, etc.

anhydride, anhydride,

Examples 1-12 In the following examples, various proportions of3,4-epoxy-6-methylcyclohexylmethyl3,4-epoxy-6-methylcyclohexanecarboxylate were mixed with oxidizedstannous octoate catalyst and various active organic hardeners.

The procedure for testing the catalyst with the epoxide and varioushardeners, as summarized in Table I, was as follows: In general, theepoxide and hardener were mixed at room temperature, warmed to theminimum temperature necessary for solution to occur and catalyst added.After bringing the contents of the tubes to 150 C., the tubes wereclosed and placed in the oven at this temperature. In every case, thecatalyst caused the liquid mixtures to gel much more rapidly and produceharder resins than the controls. Even in those cases where gels at 150C. were not observed, use of catalysts gave much thicker liquids at roomtemperature. In all experiments the total resin charge was 23 grams and0.23 gram (1.0 percent) of catalyst was used. Unless otherwise indicatedall resins were cured for 22 hours at 150 C.

14 indicated absorption maxima at 3.6;t-3.9'p. (broad acid --OH); 5.89(free acid C=O); 6.45 and 6.85 1.

TABLE I Hardener Oxidized Ex Epoxlde; Stannous Ratio a Gel Time Barcol bNo Gms. Octoate, at 150 0.

Name Gms. Gms.

20. 1 1,2,6-hexanetriol 2. 9 0.23 1:0. 5 3-22 hrs. 20. 1 do 2. 9 1:0. 5None Liq. 16. 7 6.3 0.23 1:0. 5 0-5 mins--.. 30 16.7 .....(10 6.3 1:0.56-22 hrs.-..- 0 14. 5 Methyl N adie Anhydride 8. 5 0. 23 1:1 33-38 mms-14.5 o 8.5 1:1 6-22hrs 14. 7 Toluenediisoeyanate 8. 3 0. 23 1:1 24-29mins. 25 14. 7 8. 3 1:1 6-22 hrs Soft 17.3 5.7 0.23 1:0.5 0-3 mins....22 17.3 5. 7 1:0. 5 1.5-1.75 hrs.- 0 11.5 11.5 0.23 1:05 0-7 mins--..11.5 11.5 1:0. 5 6-22 hrs I Ratio of Epoxide to reactive or functionalgroup.

b Barcol Impressor GYZJ934-1 was used to determine Barcol No.

a 3,4-epoxy-6-methylc elohexylmethyl3,4epoxy-6-methylcyclohexauecarboxylate.

d Methylb1cye1o-[2.2.1 heptane-2,3-dicarboxylic acid anhydride.

s percent 2,6- and 80 percent 2,4-isomer.

! Emery Empol 1022 Dimer acid; 578 mol. wt., neutralizationequivalent=300.

Ex mples 13-22 H The following examples demonstrate. the effectiveness(ester of the oxidized stannous octoate catalyst with various types ofpolyepoxide-s and an anhydride hardener. The catalyst was added to ahomogeneous solution as before and the curing was performed at thetemperature and for the periods indicated. The results obtained aregiven in Table II below.

TABLE II In a similar manner other catalysts can be prepared by theoxidation of, for example, stannous acetate, stannous propionate,stannous oxalate, stannous tartrate, stannous butyrate, and the like.

Although the invention has been illustrated by the preceding examples,it is not to be construed as limited to Methyl N adic Anhydride,

Gms.

Epoxide b Gms. Ratio a Catalyst,

Gms.

Gel Time at 150 C.

Cure at 150 0., Hrs.

[OM Rimicnolomoaczo:

I Ratiopt epoxide to reactive or functional group.

b Epoxide A=vinyleyclohexene dioxide.

Epoxide B =bis(3,4-epoxy-fi-methyleyelohexylmethyl)adipate. EpoxideC=soybean oil epoxide.

Epoxide D =1,2,3-propanetriol tris-(3,4-epoxycyclohexanecarboxylate).

Epoxide E=1,1,1-trimethylolpropanetris-(3,4-epoxyoyelohexanecarboxylate).

Example 23.--Preparati0n of oxidized stannous octoate To a two-literfour-neck flask equipped with thermometer, water cooled condenser,mechanical stirrer, drying tower, wet meter and flow meter, were added500 grams of stannous octoate. The contents of the flask was stirredvigorously while dry oxygen was passed over the liquid at an averagerate of 0.389 liter per minute for a total period of three hours andforty five minutes. The oxygen was measured entering the flask with acalibrated flow meter and leaving the flask with a wet meter. At thebeginning of the reaction the flask was at room temperature, i.e.,approximately 26 C. thereafter it was heated gradually to about 120 l25C. over a two hour period. At the completion of the reaction the flaskwas cooled, the oxygen flow stopped. 12.96 liters of oxygen had beenconsumed during the reaction as evidenced by the difference in flowmeter and wet meter readings. Analysis of the oxidized stannous octoateindicated the following: Calculated for C H O Sn: Sn, 28.2; C, 45.7; H,7.2. Found: Sn, 28.2; C, 45.03; H, 7.16; refraction index, N =1.4835;molecular weight: Calculated for C H O Sn 842. Found: 762 and 923(ebullioscopicin benzene). Infrared spectrum the materials employedtherein, but rather, the invention encompasses the generic area ashereinbefore disclosed.

Various modifications and embodiments of this invention can be madewithout departing from the spirit and scope thereof.

What is claimed is:

1. Oxidized stannous acylate of the formula:

wherein R is a monovalent hydrocarbon radical of from 1 to 24 carbonatoms and free of acetylenic and aromatic unsaturation.

2. The oxidized stannous acylate of claim 1 wherein each R is heptyl.

No references cited.

ALEX MAZEL, Primary Examiner.

C. B. PARKER, Examiner.

A. H. SUTTO, J. A. NARCAVAGE,

' Assistant Examiners.

1. OXIDIZED STANNOUS ACYLATE OF THE FORMULA: